Line | Count | Source (jump to first uncovered line) |
1 | | /* fclose replacement. |
2 | | Copyright (C) 2008-2025 Free Software Foundation, Inc. |
3 | | |
4 | | This file is free software: you can redistribute it and/or modify |
5 | | it under the terms of the GNU Lesser General Public License as |
6 | | published by the Free Software Foundation; either version 2.1 of the |
7 | | License, or (at your option) any later version. |
8 | | |
9 | | This file is distributed in the hope that it will be useful, |
10 | | but WITHOUT ANY WARRANTY; without even the implied warranty of |
11 | | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
12 | | GNU Lesser General Public License for more details. |
13 | | |
14 | | You should have received a copy of the GNU Lesser General Public License |
15 | | along with this program. If not, see <https://www.gnu.org/licenses/>. */ |
16 | | |
17 | | #include <config.h> |
18 | | |
19 | | /* Specification. */ |
20 | | #include <stdio.h> |
21 | | |
22 | | #include <errno.h> |
23 | | #include <unistd.h> |
24 | | |
25 | | #include "freading.h" |
26 | | #if HAVE_MSVC_INVALID_PARAMETER_HANDLER |
27 | | # include "msvc-inval.h" |
28 | | #endif |
29 | | |
30 | | #undef fclose |
31 | | |
32 | | #if HAVE_MSVC_INVALID_PARAMETER_HANDLER |
33 | | static int |
34 | | fclose_nothrow (FILE *fp) |
35 | | { |
36 | | int result; |
37 | | |
38 | | TRY_MSVC_INVAL |
39 | | { |
40 | | result = fclose (fp); |
41 | | } |
42 | | CATCH_MSVC_INVAL |
43 | | { |
44 | | result = EOF; |
45 | | errno = EBADF; |
46 | | } |
47 | | DONE_MSVC_INVAL; |
48 | | |
49 | | return result; |
50 | | } |
51 | | #else |
52 | 0 | # define fclose_nothrow fclose |
53 | | #endif |
54 | | |
55 | | /* Override fclose() to call the overridden fflush() or close(). */ |
56 | | |
57 | | int |
58 | | rpl_fclose (FILE *fp) |
59 | 0 | { |
60 | 0 | int saved_errno = 0; |
61 | 0 | int fd; |
62 | 0 | int result = 0; |
63 | | |
64 | | /* Don't change behavior on memstreams. */ |
65 | 0 | fd = fileno (fp); |
66 | 0 | if (fd < 0) |
67 | 0 | return fclose_nothrow (fp); |
68 | | |
69 | | /* We only need to flush the file if it is not reading or if it is |
70 | | seekable. This only guarantees the file position of input files |
71 | | if the fflush module is also in use. */ |
72 | 0 | if ((!freading (fp) || lseek (fileno (fp), 0, SEEK_CUR) != -1) |
73 | 0 | && fflush (fp)) |
74 | 0 | saved_errno = errno; |
75 | | |
76 | | /* fclose() calls close(), but we need to also invoke all hooks that our |
77 | | overridden close() function invokes. See lib/close.c. */ |
78 | | #if WINDOWS_SOCKETS |
79 | | /* Call the overridden close(), then the original fclose(). |
80 | | Note about multithread-safety: There is a race condition where some |
81 | | other thread could open fd between our close and fclose. */ |
82 | | if (close (fd) < 0 && saved_errno == 0) |
83 | | saved_errno = errno; |
84 | | |
85 | | fclose_nothrow (fp); /* will fail with errno = EBADF, |
86 | | if we did not lose a race */ |
87 | | |
88 | | #else /* !WINDOWS_SOCKETS */ |
89 | | /* Call fclose() and invoke all hooks of the overridden close(). */ |
90 | |
|
91 | | # if REPLACE_FCHDIR |
92 | | /* Note about multithread-safety: There is a race condition here as well. |
93 | | Some other thread could open fd between our calls to fclose and |
94 | | _gl_unregister_fd. */ |
95 | | result = fclose_nothrow (fp); |
96 | | if (result == 0) |
97 | | _gl_unregister_fd (fd); |
98 | | # else |
99 | | /* No race condition here. */ |
100 | 0 | result = fclose_nothrow (fp); |
101 | 0 | # endif |
102 | |
|
103 | 0 | #endif /* !WINDOWS_SOCKETS */ |
104 | |
|
105 | 0 | if (saved_errno != 0) |
106 | 0 | { |
107 | 0 | errno = saved_errno; |
108 | 0 | result = EOF; |
109 | 0 | } |
110 | |
|
111 | 0 | return result; |
112 | 0 | } |